1.
Rev Sci Instrum
; 84(8): 084905, 2013 Aug.
Article
in English
| MEDLINE
| ID: mdl-24007094
ABSTRACT
We describe a simple method to measure the back-bombardment heating temperature rise as a function of time in pulsed microwave thermionic guns using a fast rise-time InGaAs detector and optical pyrometer. Gaining knowledge of the nature of that temperature rise and the corresponding current out of the gun are the first steps in devising a scheme to counteract the back-bombardment heating which lengthens the micropulses, limits the macropulse length, and increases the energy spread of the emitted electron beam. We measured a temperature rise of 59 K in our LaB6 cathode which delivered a peak of 600 mA over a 5 µs RF pulse in our 0.33 MV/cm peak field, 2.856 GHz thermionic electron gun.